GERD is caused by abnormal regurgitation of acid fluids from the stomach into the esophagus. The stomach generates strong acids to aid digestion. The esophagus is normally protected from these acids by a one-way valve mechanism at its junction with the stomach. This one-way valve is called the lower esophageal sphincter (LES). In patients with GERD, the LES frequently malfunctions because it is either too weak or too short. The short or weak LES cannot retain the contents of the stomach as it fills up and pressure inside rises.
When the LES falls, acid flows backwards—refluxes—up into the esophagus which is not designed to handle it. The result is an acid burn, commonly called “heartburn”, or “acid indigestion”. Heartburn feels like a burning or pressure pain behind the breastbone—it may feel very much like a heart attack. When the acid is in the esophagus, and one belches, it may regurgitate up into the back of the throat, tasting sour or bitter, and causing a burning sensation. If this occurs at night, one may wake-up with either a hot, fiery feeling in the back of the throat, or even coughing and gasping resulting from acid entering the breathing tubes. This last phenomenon is called Reflux Nocturnal Aspiration and can be quite serious in itself.
Reflux Nocturnal Aspiration can be dangerous, because it introduces acid and bacteria into the airway and lungs. This can cause recurrent bronchitis, pneumonia, lung abscess, or chronic scarring of the lung. It can also lead to asthma attacks in those with an asthmatic tendency.
When acid reflux and these symptoms occur daily or up to three or four times weekly, the esophagus cannot withstand the damaging effects of the acid bath and becomes inflamed, especially at its lower part. Swallowing can frequently be painful, and food may stick in the chest. This is called reflux esophagitis, meaning inflammation of the esophagus due to acid reflux. Persistent esophagitis can cause erosions and ulcers and lead to scarring and narrowing and also irreversible injury to the esophagus.
In some patients, as the esophageal lining becomes increasingly damaged and the body may attempt to try to protect it by changing the lining material to a more resistant type, such as found in the intestine. This change, called Barrett's Esophageal Metaplasia, or Barrett's Esophagus, does not make the symptoms disappear but actually produces a new problem. Metaplastic changes increase the risk of a cancer forming in the new and abnormal lining. Adenocarcinoma of the Gastresophageal Cardia is a highly malignant and fatal type of cancer, the incidence of which is increasing rapidly in America. Some authorities believe that Barrett's esophagus is caused by bile reflux and that the rising incidence of this particular type of cancer is due to the increasing use of medication that suppresses acid production, thus allowing the alkaline bile to reflux unopposed into the esophagus.
The symptoms of acid reflux are uncomfortable, and some sort of relief is usually sought. Some patients chew antacid tablets, sleep on several pillows, or even sleep upright in a recliner. Those with frequent symptoms are treated with drugs that interfere with the formation of acid in the stomach such as Tagamet®, Zantac®, Pepcid®, and Prilosec®. These medications work well in relieving symptoms, till the next dose is due, but they have to be taken daily, often for life, and the cost is substantial (around $1,300 per patient per year).
Moreover, these medications relieve the symptoms, but do not correct the underlying problem.
Currently, the only way to restore the valve function is to operate under a general anesthetic. In the past, the operation was a complex undertaking, entailing a large abdominal or thoracic incision, a lengthy stay in hospital, and a prolonged absence from work. Today, the operation can be done laparoscopically. This shortens the hospital stay, from about ten days to two or three days, but is still carried on under a general anesthetic, and is associated with a significant complication rate, Therefore gastroenterologists are often reluctant to refer patients to surgeons for anti-reflux surgery and many patients who should be operated upon are not.
It is estimated that in the USA alone, 65 million people suffer from heartburn and GERD symptoms are currently the most common complaint of patients who consult with gastroenterologists. According to the New England Journal of Medicine, nearly 40% of adult Americans suffer from heartburn; of those who seek treatment for symptoms of reflux esophagitis, 10 to 20% have serious complications (about 4–8% of the total adult population).